Apparatus for bulk drying of sliced and granular materials

Abstract

A heated airflow dryer system for drying granular, crushed, and in particular, sliced fruit and other crops and materials where granules are of at least about one quarter inch diameter or slices are about one quarter inch or more thickness. An integral or removable materials holding container has multiple removable airflow plates configured with airflow channels extending through the container interior connecting an inlet high pressure plenum to a lower pressure outlet plenum of a primary heated airflow circuit. The airflow plates are parallel and uniformly spaced to form vertical or horizontal bays of sufficient width to hold the granules or slices. The primary airflow is directed through the container. An air dryer removes excess moisture in the primary airflow or a secondary airflow circuit, which may incorporate a heat exchanger, exhausts moist air and provides make up air to the primary airflow.

I claim:  
     
       1. A dryer system for drying materials of uniform thickness comprising: 
       a container for holding said materials for drying,  
       a high pressure plenum communicating with a first ventilated surface of said container,  
       a low pressure plenum communicating with an opposing ventilated surface of said container;  
       a plurality of parallel and uniformly spaced airflow plates disposed within said container, said airflow plates configured with open wall airflow channels connecting said inlet plenum to said outlet plenum,  
       a primary airflow circuit comprising a connecting airway running from said low pressure plenum to said high pressure plenum and hence through said container and into said low pressure plenum,  
       a primary airflow sustainable by an air mover, and  
       means for removing moisture from said primary airflow.  
     
     
       2. A dryer system for drying materials of uniform thickness according to  claim 1 , further comprising means for heating said primary airflow. 
     
     
       3. A dryer system for drying materials of uniform thickness according to  claim 2 , further comprising means for controlling said means for heating. 
     
     
       4. A dryer system for drying materials of uniform thickness according to  claim 2 , said means for heating said primary airflow comprising a solar permeable enclosure. 
     
     
       5. A dryer system for drying materials of uniform thickness according to  claim 2 , said means for heating said primary airflow comprising a heater in said airway. 
     
     
       6. A dryer system for drying materials of uniform thickness according to  claim 5 , said heater configured proximate said fan. 
     
     
       7. A dryer system for drying materials of uniform thickness according to  claim 1 , said means for removing moisture from said primary airflow comprising an air dryer to which said primary airflow is exposed. 
     
     
       8. A dryer system for drying materials of uniform thickness according to  claim 1 , said means for removing moisture from said primary airflow comprising a secondary airflow of make up air and exhaust air to which said primary airflow is exposed, and a means for sustaining said secondary airflow. 
     
     
       9. A dryer system for drying materials of uniform thickness according to  claim 8 , said means for sustaining said secondary airflow comprising an inlet for said make up air configured in said low pressure plenum and an outlet for said exhaust air configured in said high pressure plenum. 
     
     
       10. A dryer system for drying materials of uniform thickness according to  claim 9 , at least one of said inlet and said outlet being adjustable for controlling the rate of said secondary airflow relative to the pressure differential between said inlet and said outlet. 
     
     
       11. A dryer system for drying materials of uniform thickness according to  claim 8 , said means for sustaining said secondary airflow comprising an inlet for said makeup air and an outlet for said exhaust, at least one of which is configured with a fan. 
     
     
       12. A dryer system for drying materials of uniform thickness according to  claim 8 , said secondary airflow further comprising a heat exchanger for transferring heat from said exhaust air to said make up air heat. 
     
     
       13. A dryer system for drying materials of uniform thickness according to  claim 1 , said dryer system comprising a greenhouse, said means for removing moisture from said primary airflow comprising a secondary airflow of make up air and exhaust air to which said primary airflow is exposed, and a means for sustaining said secondary airflow. 
     
     
       14. A dryer system for drying materials of uniform thickness according to  claim 1 , said airflow plates oriented as horizontal bays within said container. 
     
     
       15. A dryer system for drying materials of uniform thickness according to  claim 1 , said airflow plates oriented as vertical bays within said container. 
     
     
       16. A dryer system for drying materials of uniform thickness according to  claim 15 , said container configured for top feeding and underside removal of said materials of uniform thickness. 
     
     
       17. A dryer system for drying materials of uniform thickness, comprising: 
       a materials container for holding said materials for drying,  
       a high pressure plenum communicating with a first ventilated surface of said container,  
       a low pressure plenum communicating with an opposing ventilated surface of said container;  
       a plurality of parallel and uniformly spaced corrugated airflow plates disposed within said container so as to define bays of at least said uniform thickness, said airflow plates configured with open wall airflow channels connecting said inlet plenum to said outlet plenum,  
       a primary airflow circuit comprising a connecting airway running from said low pressure plenum to said high pressure plenum and hence through said container and into said low pressure plenum,  
       a primary airflow sustainable by a fan,  
       a solar permeable enclosure for heating said primary airflow,  
       means for removing moisture from said primary airflow.  
     
     
       18. A dryer system for drying materials of uniform thickness according to  claim 17 , further comprising a heater in said airway for heating said primary airflow. 
     
     
       19. A dryer system for drying materials of uniform thickness according to  claim 17 , said means for removing moisture from said primary airflow comprising an air dryer to which said primary airflow is exposed. 
     
     
       20. A dryer system for drying materials of uniform thickness according to  claim 17 , said means for removing moisture from said primary airflow comprising a secondary airflow of make up air and exhaust air to which said primary airflow is exposed, and further comprising a heat exchanger for transferring heat from said exhaust air to said make up air heat. 
     
     
       21. A dryer system for drying materials of uniform thickness according to  claim 17 , said materials of uniform thickness being sliced fruit. 
     
     
       22. A dryer system for drying materials of uniform thickness according to  claim 17 , said materials of uniform thickness being coffee beans, said bays being vertically oriented and extending to more than four feet, said airflow channels being horizontally oriented. 
     
     
       23. A dryer system for drying sliced materials of uniform thickness comprising: 
       a container for holding said sliced materials for drying,  
       an inlet plenum communicating with a first ventilated surface of said container,  
       an outlet plenum communicating with an opposing ventilated surface of said container,  
       a plurality of parallel and uniformly spaced airflow plates disposed within said container so as to define a parallel set of bays of uniform thickness, said airflow plates configured with open wall airflow channels connecting said inlet plenum to said outlet plenum,  
       means for exerting a pressure differential between said inlet plenum and said outlet plenum so as to maintain an airflow through said container.  
     
     
       24. A dryer system for drying sliced materials of uniform thickness according to  claim 23 , further comprising means for heating said airflow to higher than ambient temperature. 
     
     
       25. A dryer system for drying sliced materials of uniform thickness according to  claim 24 , further comprising means for controlling said means for heating. 
     
     
       26. A dryer system for drying sliced materials of uniform thickness according to  claim 23 , said means for exerting a pressure differential comprising a fan proximate one of said inlet plenum and said outlet plenum. 
     
     
       27. A dryer system for drying sliced materials of uniform thickness according to  claim 24 , said means for heating said airflow comprising a solar permeable enclosure. 
     
     
       28. A dryer system for drying sliced materials of uniform thickness according to  claim 27 , said means for heating said airflow comprising a heater proximate said inlet plenum. 
     
     
       29. A dryer system for drying sliced materials of uniform thickness according to  claim 23 , said airflow plates oriented as horizontal bays within said container. 
     
     
       30. A dryer system for drying sliced materials of uniform thickness according to  claim 23 , said airflow plates oriented as vertical bays within said container, said airflow channels being vertically oriented. 
     
     
       31. A dryer system for drying sliced materials of uniform thickness according to  claim 30 , said container configured for top feeding and underside removal of said materials of uniform thickness. 
     
     
       32. A dryer system for drying sliced materials of uniform thickness according to  claim 23 , said materials of uniform thickness comprising sliced fruit.